Small ResourceManager refactor, add ResourceSaver<T>.

DaggerFramework/Source/SceneGraph/EntityLayer.cs

@@ -1,3 +1,4 @@
+using System.Text.Json.Serialization;
 using DaggerFramework.Rendering;
 using DaggerFramework.Utils;
 
@@ -5,17 +6,17 @@ namespace DaggerFramework.SceneGraph
 {
     public class EntityLayer : Layer
     {
-        public List<Entity> Entities { get => _entities; }
+        [JsonInclude] public List<Entity> Entities { get; set; }
         public Camera2d? CurrentCamera { get; set; }
 
         public EntityLayer(List<Entity> entities)
         {
-            _entities = entities;
+            Entities = entities;
         }
 
         public EntityLayer()
         {
-            _entities = new List<Entity>();
+            Entities = new List<Entity>();
         }
 
         public void UpdateCurrentCamera()
@@ -53,14 +54,14 @@ namespace DaggerFramework.SceneGraph
 
         public void DestroyEntity(int at)
         {
-            _entities.RemoveAt(at);
+            Entities.RemoveAt(at);
         }
 
         protected override void OnStart()
         {
-            for (int i = 0; i < _entities.Count; i++)
+            for (int i = 0; i < Entities.Count; i++)
             {
-                var entity = _entities[i];
+                var entity = Entities[i];
                 entity.Layer = this;
                 entity.Start();
             }
@@ -68,7 +69,7 @@ namespace DaggerFramework.SceneGraph
 
         protected override void OnUpdate(double dt)
         {
-            foreach (var entity in _entities)
+            foreach (var entity in Entities)
             {
                 entity.Update(dt);
             }
@@ -94,7 +95,7 @@ namespace DaggerFramework.SceneGraph
         protected override void OnDraw(Renderer renderer)
         {
             // TODO: can be done more efficiently, needs rendering redesign.
-            foreach (var entity in _entities)
+            foreach (var entity in Entities)
             {
                 if (entity is IDrawable drawable)
                 {
@@ -102,8 +103,6 @@ namespace DaggerFramework.SceneGraph
                 }
             }
         }
-
-        private List<Entity> _entities;
         private List<Camera2d> _cameraEntities = new();
     }
 }